It becomes girl in large town to be elegant (6)
I believe the answer is:
classy
'be elegant' is the definition.
(I've seen this before)
'it becomes girl in large town' is the wordplay.
I cannot really see how this works, but
'girl' could be 'lass' (lass can informally mean a girl) and 'lass' is found in the answer.
This explanation may well be incorrect...
'to' acts as a link.
Can you help me to learn more?
(Other definitions for classy that I've seen before include "showing style ..." , "Sophisticated (colloq.)" , "Elegant and fashionable, posh" , "Stylish (slang)" , "Sophisticated, stylish" .)